The present invention relates to a power supply system of a vehicle, such as an automotive vehicle.
Conventionally, in a power supply system for supplying power to plural electric loads (electric devices) arranged at a vehicle, such as an automotive vehicle, a relay device is connected to a battery (electric storage device) by a power line and the electric loads are connected to the relay device by other power lines (distribution power lined), so that power from the battery is distributed to the respective electric loads by way of the relay device. In this case, it has been tried to reduce the number of power lines as disclosed in Japanese Patent Laid-Open Publication Nos. 2008-284098 or 2005-178778. Reduction of the number of power lines causes shortening of the entire length of the power lines and decreasing of the gross weight of the power lines, so that the weight reduction and the cost reduction of the power supply system can be achieved.
Herein, the gross weight of the power lines depends not only on the number of the power lines or the lines' length but on the lines' diameter. Accordingly, in a case in which the power lines having the larger diameter are used in order to achieve the reduction of the number of the power lines, the gross weight of the power lines becomes improperly heavier.